Knotter lock for tying machine



1966 D. A. GREGORY ETAL 3,

KNOTTER LOCK FOR TYING MACHINE Filed May 4, 1965 2 Sheets-Sheet 1 Lum -1I Q MM g I I/Mn 10 6 INVENTOFZS ELTON E. 552m BY DOUGLAS AGREGORY 1966 D. A. GREGORY ETAL 3,

KNOTTER LOCK FOR TYING MACHINE Filed May 4, 1965 2 Sheets-Sheet 2 INVENTOQS ELTON E. BEQQY DOUGLAS A. GIQEGORY BY Wm, (9M4, 6M (6W 3,294,431 KNOTTER LOCK FOR TYING MACHINE Douglas A. Gregory and Elton E. Berry, Chicago, 111.,

assignors to B. H. Bunn Company, Chicago, 111., a corporation of llllinois Fitted May 4, 1965, Ser. No. 453,100 6 Claims. (6i. 289-48) This invention relates to tying machines for tying bundles, packages, or the like, and particularly to a lock for the knotter thereof.

In tying machines of the type disclosed in B. H. Bunn United States Patent No. 1,606,290, dated November 9, 1926, for Tying Machine, at knotter isused which is driven intermittently in timed relation with the wrapping of a reach of twine around the bundle or package being tied. The knotter incorporates a beak which holds the twine while the knot is being tied and before the twine is severed by a knife. It sometimes occurs that the operator of the machine will attempt to remove a package from a tying machine before the twine is severed. The pull exerted upon the twine by the package as the latter is moved prematurely by the operator, tends to turn the beak and leave it in a turned position, so that it is not correctly oriented for the succeeding knot-tying operation. As a result, the second tying operation is defective and there is also a possibility that the pinion for the knotter will be damaged, since the initial engagement thereof by the drive gear therefor is through a specially relieved tooth which is rotated out of engagement with the drive gear.

The solution to the foregoing problem is to provide a locking mechanism for the knotter so that the knotter, after it performs its function, is prevented from rotating, even though it may be under tension produced by the twine when the package or bundle to be tied is prematurely pulled off the machine. One such knotter lock is disclosed and claimed in a co-pending application of Lurie, Serial No. 313,221, filed October 2, 1963. In said prior knotter lock a pivoted latch is used which is normally biased by a spring to engage the pinion which drives the knotter beak, but the latch is withdrawn from the pinion by a cam operated by the intermittent driving mechanism for the beak. Although this mechanism operates satisfactorily, it is amongthe general objects of this invention to simplify and render less expensive a knotter lock for the drive mechanism of the knotter of the tying machine.

As a more specific object, this invention has within its purview the provision of a sliding bolt-type of locking mechanism for the knotter of a tying machine, which will be less expensive to make and which will occupy less space than the knotter lock of the prior art.

A further specific object of this invention is to provide a knotter lock for a tying machine which will be simple and certain in operation and which can be readily maintained in good working order.

These and other objects of this invention will become apparent from the following detailed description of a preferred embodiment thereof when taken together with the accompanying drawings in which FIG. 1 is a side elevational view of a knotter for a tying machine and a portion of the drive mechanism therefor to which this invention has been applied;

FIG. 2 is a rear elevational view of a portion of the mechanism of FIG. 1 looking in the direction of the arrows at the ends of line 22 thereof;

FIG. 3 is a perspective view of the lock plunger portion of the invention shown in FIG. 1;

FIG. 4 is a fragmentary plan view of the lock plunger and associated apparatus taken along line 4-4 of FIG. 1 and looking in the direction of the arrows at the ends thereof;

nited States Patent 3 ,294,431 Patented Dec. 27, 1966 FIG. 5 is a view corresponding to FIG. 4 but showing the lock mechanism in an unlocked condition; and

FIG. 6 is a rear elevational view of the mechanism of FIG. 1 corresponding to FIG. 2 but showing the drive mechanism for the knotter after it has performed its function.

A typical machine to which this invention may be applied is disclosed in the aforementioned B. H. Bunn Patent No. 1,606,290, dated November 9, 1962, for Tying Machine. The details of the tying machine other than the knotter and the immediate drive therefor are not a part of this invention and accordingly will not be described herein. Each such machine, however, employs a knotter which, during the performance of its function, is rotated in relation to the twine to be tied, in a manner to tie a knot in the twine, and the rotation of the knotter through 360 is an essential portion of the tying function. The drive for the knotter is an interrupted gear which, as part of the tying cycle, is made to engage a drive gear or pinion for the knotter during a predetermined portion of the tying cycle of the machine and to release the knotter, that is, to disengage itself from the pinion during the remaining portion of the tying function of the machine. While the pinion is disengaged, certain other portions of the tying cycle take place, such as the stripping and cutting of the twine, and during these portions of the cycle a resiliently held friction device is depended upon to hold the knotter in place. The resilient device, however, is yieldable, and should the bundle be moved before the stripping and cutting functions are completed, the knotter itself may be rotated through a portion of its cycle and left there in an out-of-phase condition when the next knotting cycle is to take place. It is to the solution of this problem that the aforesaid Lurie application and this invention are addressed.

Referring now to the drawings for a detailed description of the invention and particularly to FIG. 1, there is shown a knotter frame 10 which, for the performance of certain of the functions of the knotter, is mounted oscillatably on a shaft 11 and is provided with a knotter beak 12. Said knotter beak is secured to a shaft 13 by a pin 14, or the like, said shaft 13 extending downwardly out of frame 10 and having a bevel gear 15 secured to it which meshes with a bevel gear 16 mounted on a shaft 17 extending through and journalled in frame 10. On the opposite end of shaft 17 from bevel gear 16 is mounted a drive pinion 18 which derives its drive from an interrupted gear 19. The latter is mounted for rotation with the drive shaft 20 and is in fact a gear sector secured to a casting 21 by screws 22 (FIG. 2), or the like, the casting 21 in turn being appropriately secured for rotation with said shaft 20.

As shown more clearly in FIG. 2, gear section 19 is designed to be rotated in counter-clockwise direction as viewed in FIG. 2, around drive shaft 20, past pinion 18. The teeth of gear sector 19 are adapted to engage the teeth of pinion 18 and to facilitate such engagement, one of the teeth 23 of the pinion 18 is relieved as at 24, to enable the lead tooth 25 of the gear sector 19 to enter the space immediately in front of relieved tooth 23. The length of the gear sector 19 determines the amount of rotation to be imparted to pinion 18. As may be apparent from FIG. 2, the number of teeth on sector 19 is such as the ensure a 360 rotation of pinion 18. This means that with a one-to-one ratio between bevel gears 15 and 16 the knotter beak 12 will similarly be rotated through exactly 360 so that it will always commence its cycle from a predetermined orientation relative to the knotter frame 10.

It may be apparent that since shaft 20 will make a single, complete revolution for each knot-tying cycle, and since gear sector 19 represents only a small portion of 360, that pinion 18 will be free of sector 19 for the greater portion of the operation of the tying machine. It is desirable for uniformity of results that said pinion 18 remains in the position shown in FIG. 2 at all times while it is not in contact with sector 19, so that it can always commence its cycle from the same position. The improved means for accomplishing this result will now be described.

The locking means which holds pinion 18 against rotation with respect to frame is a sliding bolt mounted in the knotter frame 10 and so disposed in frame 10 as to enter a space between adjacent teeth on pinion 18. The bolt is shown in FIG. 1 at 26 and is in the form of a plunger of cylindrical cross-section which is formed with an axially extending central pin 27 which centers a helical spring 28 disposed in a recess 29 located concentrically with respect to a recess 30 in which the plunger 26 is adapted to reciprocate. As shown more clearly in FIG. 3, said plunger 26 has a tooth 31 formed in its upper half which is disposed in alignment with a space between adjacent teeth on pinion 18. Said plunger is maintained in a predetermined orientation relative to pinion 18 by a guide screw 32 (FIG. 4) which may be in the form of a set screw and which accordingly is threadedly received in a suitable opening 33 in the side of knotter frame 10. A lock nut 34 engaging the exterior end of screw 32 serves to maintain said screw in a predetermined location in frame 10. The inner end 35 of screw 32 is received in an axial groove 36 in the side of plunger 26, so that said plunger may reciprocate in its recess 30, but is prevented from turning therein by the inner end 35 of screw 32.

The outer end 37 of plunger 26 has a chamfer 38 around the perimeter thereof which is adapted to be engaged by a cam 39 secured to gear sector 19 so as to be rotatable therewith. Thus, as shaft rotates and drives gear sector 19 with it, it likewise carries cam 39 which engages the chamfer 38 and forces plunger 26 into its recess against the action of spring 28. The inner position of the plunger is shown in FIG. 5. The opposite end 40 of the cam 39 is oppositely sloped so that as the cam leaves plunger 26 said surface 40 engages chamfer 38 and allows plunger 26 to move outwardly under the action of spring 28. It may be noted that axial groove 36 also provides a means for allowing air to move freely into and out of recess behind plunger 26.

In its projected position plunger 26 is held against leaving its recess 30 by the engagement of surfaces 41 and 42 (FIGS. 3 and 6) disposed on either side of tooth 31 with the sides of the gear teeth of the pinion 18. Said pinion 18 is wider (i.e. of greater axial extent) than the gear sector 19 as shown in FIG. 1, so that plunger 26 will not extend into the path of movement of said gear sector 19 and yet will engage the pinion 18 to perform its stated holding function.

The operation of the knotter beak holding device is quite simple. Whenever cam 39 passes in front of plunger 26, it pushes the plunger into its recess and holds it there. The width of the cam measured axially of gear sector 19 is greater than the axial length of the tooth 31 on the plunger, so that the tooth is completely disengaged from pinion 18 whenever cam 39 is in engagement with the outer end 37 of plunger 26. When, however, the cam 39 is not in engagement with the outer end 37 of plunger 26, said plunger is pushed outwardly of its recess 30 by spring 28 and into engagement with gear 18. The timing is such that just as the trailing tooth 43 (FIG. 6) of the gear sector 19 begins to disengage itself from the corresponding tooth 44 on pinion 18, tooth 31 begins. to enter the space adjacent tooth 23. In a typical example, during a rotation of three degrees from the point of contact of the cam with plunger 26, the cam depressed plunger 26, and a further rotation of two degrees beyond the depression of the cam caused the gear sector 19 to engage the pinion 18 and begin to rotate said gear. The release of plunger 26 was effected in the reverse order, that is, gear sector 19 left pinion 18 in two degrees of rotation of the gear sector, and the tooth 31 entered the space between adjacent teeth on pinion 18 in the next three degrees of rotation of the gear sector 19.

It may be apparent from the description given above that the knotter lock of this invention is very simple and inexpensive and can be readily incorporated into the frame 10 of the knotter where it occupies very little space. Its function is automatic and does not require any major change in the drive for the pinion 18.

It is understood that the foregoing description is merely illustrative of a preferred embodiment of this invention and that the scope of the invention therefor is not to be limited thereto, but is to be determined by the appended claims.

We claim:

1. In combination, a frame, a rotatable knotter beak on the frame, intermittent drive means for the beak, including a pinion gear, a shaft rotatable in the frame and driven by the pinion gear, means connecting the shaft to the beak, and an interrupted gear adapted to engage and drive the pinion gear; a plunger reciprocable in the frame toward and away from the pinion gear, a tooth on the plunger adapted to enter a space between adjacent teeth on the pinion gear, resilient means on the frame and bearing against the plunger to urge the plunger against the pinion gear, and means movable with the interrupted gear to engage and move the plunger away from the pinion gear.

2. The combination described in claim 1, said plunger having a cam thereon, and the means movable with the interrupted gear comprising a cam adapted to engage the cam on the plunger.

3. The combination described in claim 1, and cooperating means on the plunger and frame for preventing rotation of the plunger in the frame, but permitting reciprocation of the plunger relative to the frame.

4. The combination described in claim 1, said plunger having an axial groove in one side thereof, and a projection on the frame extending into the groove to prevent rotation of the plunger relative to the frame but permitting reciprocation of the plunger in the frame.

5. The combination described in claim 1, said tooth on the plunger being formed inwardly of a portion of the end of the plunger, and said means movable with the interrupted gear to engage and move the plunger engaging another portion of the end of the plunger.

6. The combination described in claim 1, said frame having a recess in which the plunger is reciprocable, and a second recess connected to and coaxial with the firstmentioned recess, said plunger having a coaxial pin extending into said first-mentioned recess, and said means on the frame and bearing against the plunger to urge the plunger against the pinion gear comprising a helical spring having one end thereof in the second recess its other end disposed around said pin.

References Cited by the Examiner UNITED STATES PATENTS 3,215,461 11/1965 Lurie 28918 M. STEIN, Primary Examiner.

L. K. RIMRODT, Assistant Examiner. 

1. IN COMBINATION, A FRAME, A ROTATABLE KNOTTER BEAK ON THE FRAME, INTERMITTENT DRIVE MEANS FOR THE BEAK, INCLUDING A PINION GEAR, A SHAFT ROTATABLE IN THE FRAME AND DRIVEN BY THE PINION GEAR, MEANS CONNECTING THE SHAFT TO THE BEAK, AND AN INTERRUPTED GEAR ADAPTED TO ENGAGE AND DRIVE THE PINION GEAR; A PLUNGER RECIPROCABLE IN THE FRAME TOWARD AND AWAY FROM THE PINION GEAR, A TOOTH ON THE PLUNGER ADAPTED TO ENTER A SPACE BETWEEN ADJACENT TEETH ON THE PINION GEAR, RESILIENT MEANS ON THE FRAME AND BEARING AGAINST THE PLUNGER TO URGE THE PLUNGER AGAINST THE 